service worker: navigation preload basic setters/getters and flag

content/browser/service_worker/service_worker_version.h

Index: content/browser/service_worker/service_worker_version.h
diff --git a/content/browser/service_worker/service_worker_version.h b/content/browser/service_worker/service_worker_version.h
index 5026700bcbe09f5a78f3a83a27c1700d9fe29a70..0903b1f6b75a4f09362140f572fc9fc747cbf2fb 100644
--- a/content/browser/service_worker/service_worker_version.h
+++ b/content/browser/service_worker/service_worker_version.h
@@ -171,6 +171,22 @@ class CONTENT_EXPORT ServiceWorkerVersion
 
   ServiceWorkerMetrics::Site site_for_uma() const { return site_for_uma_; }
 
+  void set_navigation_preload_enabled(bool enabled, const std::string& value) {
+    is_navigation_preload_enabled_ = enabled;
+    if (is_navigation_preload_enabled_)
+      navigation_preload_value_ = value;
+    else
+      navigation_preload_value_ = std::string();
+  }
+
+  bool is_navigation_preload_enabled() const {
+    return is_navigation_preload_enabled_;
+  }
+  const std::string& navigation_preload_value() const {
+    DCHECK(is_navigation_preload_enabled_);
+    return navigation_preload_value_;
+  }
+
   // This sets the new status and also run status change callbacks
   // if there're any (see RegisterStatusChangeCallback).
   void SetStatus(Status status);
@@ -762,6 +778,9 @@ class CONTENT_EXPORT ServiceWorkerVersion
   // FinishStartWorker().
   base::Optional<ServiceWorkerMetrics::EventType> start_worker_first_purpose_;
 
+  bool is_navigation_preload_enabled_ = false;
+  std::string navigation_preload_value_;
+
   base::WeakPtrFactory<ServiceWorkerVersion> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerVersion);